BSSN

Cloud Cover Protocol

 

Task

Observe how much of the sky is covered by clouds.

 

Frequency

Three sampling times daily (in the morning, at approximately noon, in the afternoon)

 

What You Need

  • BSSN Hazemeter Datasheet
  • five students

 

In the Field

  1. Have one student be the data recorder and complete the top section of the Datasheet.
  2. Standing back to back, the other four students should spread their arms until they touch the arms of the students next to them.
  3. The students should then raise their arms and observe the cloud coverage within their one quarter of the sky.
  4. The students should add their percentages together, and then divide by four to get the average cloud cover for the whole sky.
  5. The students will then decide which classification best matches what they see.

 

Cloud Cover Classifications

No Clouds

The sky is cloudless; there are no clouds visible

 

Clear

Clouds are present but cover less than one-tenth (or 10%) of the sky.

 

Isolated Clouds

Clouds cover between one-tenth (10%) and one-fourth (24%) of the sky.

 

Scattered Clouds

Clouds cover between one-fourth (25%) and one-half (49%) of the sky.

 

Broken Clouds

Clouds cover between one-half (50%) and nine-tenths (90%) of the sky.

 

Overcast

Clouds cover more than nine-tenths (90%) of the sky.

 

Obscured

Clouds cannot be observed because at least 1/4 of the sky cannot be seen clearly.

 

  1. If the sky is Obscured, report what is blocking the sky. Report as many of the following as are observed.

• Fog • Smoke • Haze • Volcanic Ash • Dust

• Sand • Spray • Heavy Rain • Heavy Snow • Blowing Snow

 

  1. Students should record their observations on their Datasheet.

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